US Patent 9537888 Proxy server-based malware detection

Disclosed are various embodiments for malware detection by way of proxy servers. In one embodiment, a proxy server application generates a browsing history for client devices based at least in part on proxied network resource requests received from the client devices. The proxy server application determines that at least one of the client devices is affected by malware. The proxy server application determines a source of the malware based at least in part on the browsing history or telemetry data received from the client devices. An action is implemented in response to determining the source of the malware.